1. Technical Field
The present invention relates to a non-contact IC tag having multiple antennas corresponding to multiple frequencies, to a package for a member having the non-contact IC tag, and to a device using the member having the non-contact IC tag.
2. Related Art
A very small non-contact IC tag is currently being used for identification and the like of objects. The non-contact IC tag is available in various shapes, such as a label type, a card type, a coin type, and a stick type, and a desired type can be selected depending on the intended use. The non-contact IC tag has a size of approximately several millimeters to several centimeters and can communicate with an IC tag reader/writer through a radio wave or an electromagnetic wave.
Each of the non-contact IC tag and the reader/writer is provided with a resonant circuit which includes an antenna having an inductance component and a capacitor having a capacitance component. In a case where information is to be stored in the non-contact IC tag or where information stored in the non-contact IC tag is to be read from the IC tag, the antenna in the resonant circuit of the reader/writer is brought into close proximity with the antenna in the resonant circuit of the non-contact IC tag such that the antennas are electromagnetically connected in order to transfer the information, thereby performing writing or reading while the IC tag is being supplied with power by radio waves from the reader/writer by means of non-contact power transfer technology. Thus, the non-contact IC tag can be used semi-permanently without having a battery.
The frequency used for the non-contact IC tag is roughly divided into four frequencies bands: less than 135 kHz, 13.56 MHz, 2.45 GHz, and a UHF band. Generally, communication range becomes longer as the frequency becomes higher. When a frequency of 13.56 MHz is used, the communication range becomes up to 70 to 80 cm, and when a frequency of 2.45 GHz is used, the communication distance can be up to several meters. In addition, the non-contact IC tag has a characteristic of being susceptible to an influence of peripheral moisture or metal, depending on the used frequency band; therefore, it is necessary to select a non-contact IC tag having an optimum frequency band for its intended use.
Accordingly, the non-contact IC tag having multiple antennas conforming to the individual frequency bands is currently in use. For example, a frequency band which allows relatively long-range communication is required in physical distribution management, because multiple non-contact IC tags are accessed from a relatively long distance to collectively read information and to collectively write information conforming to a shipping destination into the non-contact IC tags at the time of shipping. Meanwhile, in a case where the non-contact IC tag is attached to a device which handles highly-confidential information, such as an image forming device; for example, a copy machine, it is necessary to use a frequency band capable of communicating over only a short distance, so that a radio wave does not leak peripherally, thereby enhancing security.